Overview
ISO/TS 16774-1:2024 - "Test methods for repair materials for water‑leakage cracks in underground concrete structures - Part 1: Test method for thermal stability" defines a laboratory procedure to evaluate the thermal stress resistance of injected repair materials by measuring permeability after thermal cycling. The Technical Specification outlines specimen preparation, apparatus (temperature chamber, air compressor, permeability chamber), test procedures (thermal stress cycling and permeability testing), and reporting requirements. It provides general principles rather than fixed national testing variables, so test parameters (temperatures, cycle counts, pressures) may be adapted to local standards.
Key topics and requirements
- Scope: Laboratory evaluation of thermal stability of water‑leakage crack repair materials using permeability testing.
- Principle: Inject repair material into an artificial crack; subject specimen to repeated high/low temperature cycles; assess loss of waterproofing by permeability testing.
- Specimen preparation:
- Two flat, cylindrical concrete/mortar substrates forming an artificial crack (mix ratio given: water : cement : fine aggregate = 1 : 2 : 6 by mass).
- Pinholes (Ø 2.5 mm) in the bottom substrate to detect leakage; spacers set crack width.
- Surface cleaning and wetting prior to injection; follow manufacturer instructions where available.
- Apparatus:
- Temperature chamber capable of automatically alternating temperatures with precision ±2 °C (example range cited: −20 °C to 60 °C).
- Air compressor and permeability test chamber with typical pressure ranges noted (example 0.1 to 0.3 N/mm² - subject to national parameters).
- Procedure:
- Thermal stress cycles (high/low temperature alternation), recording mass change and visual deterioration.
- Permeability (output method) to detect leakage; photographic documentation at each stage.
- Reporting: Information required about repair material, test conditions, specimen details and observed results.
Practical applications
- Product development & QA: Manufacturers use the method to compare thermal durability of injection grouts (e.g., urethane, poly‑urea, bitumen‑based products) and to support product datasheets.
- Material selection: Engineers and specifiers evaluate which repair materials retain waterproofing after temperature fluctuations typical of underground structures.
- Laboratory testing: Independent testing labs adopt the procedure as a reference method, adapting temperature and pressure parameters to local environmental or regulatory requirements.
- Contract verification: Contractors and asset owners use test results for acceptance criteria and performance benchmarking for tunnels, basements, subway stations, utility shafts and other underground concrete works.
Who should use this standard
- Materials manufacturers (R&D, quality control)
- Construction materials testing laboratories
- Structural/repair engineers and specifiers
- Infrastructure owners and contractors
- National standards bodies developing local test parameters
Related standards
- ISO/TR 16475 - general practices for repair of water‑leakage cracks (linked reference)
- Other parts of the ISO/TS 16774 series (for additional performance property tests)
Keywords: ISO/TS 16774-1:2024, thermal stability, permeability testing, water-leakage crack repair materials, underground concrete structures, temperature cycling, test specimen, injection grouts.
Open preview (PDF)Test methods for repair materials for water-leakage cracks in underground concrete structures — Part 1: Test method for thermal stability
